Pressure bulkheads are used in vehicles, such an aircraft, to separate a pressurized compartment from an unpressurized compartment. In one typical application, a pressure bulkhead may be mounted within an aircraft fuselage and attached to the outer skin of the aircraft. Such pressure bulkhead mountings typically are complicated and heavily reinforced.
In one example, a pressure bulkhead may include an outer chord assembly composed of a machined Y-chord, failsafe angle, inner chord, and outer break rings. The bulkhead may be backed up with machined stringer end fittings at every stringer location. The stringer end fittings may have to align across a pressure bulkhead and the bulkhead is installed with heavy and complicated machined titanium Y-chord segments, an aluminum inner chord, web, and a separate bolted aluminum failsafe chord. The bulkhead may also contain a ½-inch thick CFRP (carbon fiber reinforced plastic) splice strap sandwiched between the titanium Y-chord and the fuselage skin, and the titanium stringer end fittings. The manufacturing process may require a difficult and time-consuming manufacturing configuration, drilling, deburring, and fay surface seal due to multiple different materials in stackup (e.g., CFRP, titanium, aluminum).
Such pressure bulkheads may be susceptible to corrosion and fatigue due to differences in material galvanic properties and differing coefficients of thermal expansion. For example, a pressure bulkhead having a thick stack up of skin, splice strap, and Y-chord also may require large fastener sizes (e.g., ⅜ in. diameter bolts in the crown and 5/16 in. diameter bolts in the keel) that increase weight due to fastener spacing requirements. In one aircraft application, an aft pressure bulkhead integration was redesigned in an attempt to improve efficiency of an aft pressure bulkhead (APB) chord assembly. The new configuration changed the titanium Y-chord to a T-chord and eliminated the requirements for an aluminum inner chord and failsafe chord. The APB assembly foreshortened the CFRP splice plate so it was no longer trapped between the fuselage skin and the new titanium T-chord thus reducing overall stack up and reduced fastener size (¼ in. diameter bolts all around).
Accordingly, there remains a need for a compact, lightweight and low-cost pressure bulkhead having relatively simple construction.